mac: Fix tab dragging visual bug in Yosemite.

chrome/browser/ui/cocoa/tabs/tab_window_controller.h

Index: chrome/browser/ui/cocoa/tabs/tab_window_controller.h
diff --git a/chrome/browser/ui/cocoa/tabs/tab_window_controller.h b/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
index fd41a563955531acd376524b4156221cd2042e53..ef854706f7f29c2f084a6e3eab91c7ec52b936dc 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
+++ b/chrome/browser/ui/cocoa/tabs/tab_window_controller.h
@@ -23,9 +23,19 @@
 
 @interface TabWindowController : NSWindowController<NSWindowDelegate> {
  @private
+  // Wrapper view around web content, and the developer tools view.
   base::scoped_nsobject<FastResizeView> tabContentArea_;
+
+  // The tab strip overlaps the titlebar of the window.
   base::scoped_nsobject<TabStripView> tabStripView_;
 
+  // In OSX 10.10+, all views must be added to the NSWindow's contentView. Some
+  // views (like the tab strip and the profile icon) are placed on top of the
+  // title bar and require special treatment. All other views should be added
+  // as subviews of chromeContentView_. This allows tab dragging and fullscreen
+  // logic to easily move the views that don't need special treatment.
+  base::scoped_nsobject<NSView> chromeContentView_;
+
   // The child window used during dragging to achieve the opacity tricks.
   NSWindow* overlayWindow_;
 
@@ -38,6 +48,7 @@
 }
 @property(readonly, nonatomic) TabStripView* tabStripView;
 @property(readonly, nonatomic) FastResizeView* tabContentArea;
+@property(readonly, nonatomic) NSView* chromeContentView;
 
 // This is the designated initializer for this class.
 - (id)initTabWindowControllerWithTabStrip:(BOOL)hasTabStrip;